Ядро не видит software RAID1 [Решено]

Установил корневую ФС на RAID1. Ядро не находит ФС.
В чём может быть дело?

Диски:

isds ~ # fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1           9       72261   fd  Linux raid autodetect
/dev/sda2              10        1955    15631245   fd  Linux raid autodetect
/dev/sda3            1956        5872    31463302+  fd  Linux raid autodetect
/dev/sda4            5873       60801   441217192+  fd  Linux raid autodetect

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1           9       72261   fd  Linux raid autodetect
/dev/sdb2              10        1955    15631245   fd  Linux raid autodetect
/dev/sdb3            1956        5872    31463302+  fd  Linux raid autodetect
/dev/sdb4            5873       60801   441217192+  fd  Linux raid autodetect

Disk /dev/md3: 32.2 GB, 32217298944 bytes
2 heads, 4 sectors/track, 7865551 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/md3 doesn't contain a valid partition table

mdadm:

isds ~ # cat /proc/mdstat 
Personalities : [linear] [raid0] [raid1] [raid10] [multipath] [faulty] 
md3 : active raid1 sda3[0] sdb3[1]
      31462206 blocks super 1.2 [2/2] [UU]
      
unused devices: <none>
isds ~ # mdadm --detail --scan
ARRAY /dev/md3 metadata=1.2 name=isds:3 UUID=8d49f98e:15c05216:43adf1c9:c504dd2d

grub:

isds ~ # cat /boot/grub/grub.conf 

default 0
timeout 3
title Gentoo Linux
root (hd0,0)
kernel /boot/gentoo-2.6.36-r5-2 root=/dev/md3

kernel:

isds linux # cat /usr/src/linux/.config | grep MD_          
CONFIG_AMD_IOMMU=y
CONFIG_AMD_IOMMU_STATS=y
CONFIG_MD_AUTODETECT=y
# CONFIG_MD_LINEAR is not set
CONFIG_MD_RAID0=y
CONFIG_MD_RAID1=y
CONFIG_MD_RAID10=y
# CONFIG_MD_RAID456 is not set
CONFIG_MD_MULTIPATH=y
CONFIG_MD_FAULTY=y